JP5083797B2 - Coal combustion apparatus and coal combustion method - Google Patents

Coal combustion apparatus and coal combustion method Download PDF

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JP5083797B2
JP5083797B2 JP2006236587A JP2006236587A JP5083797B2 JP 5083797 B2 JP5083797 B2 JP 5083797B2 JP 2006236587 A JP2006236587 A JP 2006236587A JP 2006236587 A JP2006236587 A JP 2006236587A JP 5083797 B2 JP5083797 B2 JP 5083797B2
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博文 辻
裕三 白井
道隆 池田
敏伸 小辻
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Central Research Institute of Electric Power Industry
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本発明は、微粉炭の燃焼状況と質を調整し排出される灰の性状を制御することができる石炭燃焼装置及び、石炭燃焼方法に関する。例えば、石炭燃焼装置として、蒸気を生成するボイラに用いて好適である。   The present invention relates to a coal combustion apparatus and a coal combustion method capable of adjusting the combustion status and quality of pulverized coal and controlling the properties of discharged ash. For example, it is suitable for use as a coal combustion apparatus in a boiler that generates steam.

現在わが国の電気は、主に化石燃料のエネルギーで作られ、その3分の1に石炭が利用されている。化石燃料から作られる電気は、火力発電所で作られており、例えば火力発電設備は我々の生活の中で重要な役割を占めている(特許文献1等参照)。   At present, Japan's electricity is mainly made from fossil fuel energy, and one-third of it uses coal. Electricity made from fossil fuels is produced at thermal power plants. For example, thermal power generation facilities play an important role in our lives (see Patent Document 1, etc.).

近年、エネルギーセキュリティーの観点から、可採埋蔵量の豊富な石炭を利用した微粉炭火力の導入が急速に進展した。その結果、石炭燃焼に伴って排出される石炭灰の量が急増し、その処理が重要な課題となっている。   In recent years, from the viewpoint of energy security, the introduction of pulverized coal thermal power using coal with abundant recoverable reserves has made rapid progress. As a result, the amount of coal ash discharged along with coal combustion increases rapidly, and its treatment is an important issue.

現在、国内で排出される石炭灰は、大半がセメント用粘土代替材料として利用されていることから、さらなる排出量の増加が予想される状況下において、新たな用途への展開が求められている。潜在的な需要規模や、灰分粒子の大半が球状である特徴を考慮した場合、セメント混和材等への利用が有望であるが、燃焼条件や石炭性状の変化に起因する石炭灰性状の変動により、本格的な利用に到っていない。また、石炭と排出する石炭灰の性状との相関は、経験によるもので明確な技術調整方法はなかった。今後、セメント混和材等への利用を拡大していくためには、石炭灰の性状を調整する技術を確立する必要がある。   Currently, the majority of coal ash emitted in Japan is used as a substitute for clay for cement. Therefore, there is a need to develop new applications in situations where further increases in emissions are expected. . Considering the potential demand scale and the characteristic that most of the ash particles are spherical, it is promising for use as a cement admixture. It has not reached full-scale use. The correlation between coal and the properties of the discharged coal ash is based on experience and there was no clear technical adjustment method. In the future, in order to expand the use to cement admixtures, it is necessary to establish a technology for adjusting the properties of coal ash.

特開2004−20140号公報Japanese Patent Laid-Open No. 2004-20140

本発明は上記状況に鑑みてなされたもので、微粉炭の燃焼によって排出される石炭灰の粒子の基礎的性状を制御することができる石炭燃焼装置及び石炭燃焼方法を提供することを目的とする。   This invention is made | formed in view of the said condition, and aims at providing the coal combustion apparatus and coal combustion method which can control the fundamental property of the particle | grains of the coal ash discharged | emitted by combustion of pulverized coal .

上記目的を達成するための本発明の第1の態様は、
微粉炭を空気と混合させて火炉内で二段燃焼させる燃焼工程を有する石炭燃焼方法であって、
質量基準の50%径である微粉炭の中位径が小さくなるほど粒子密度が大きくなるという特性に基づき前記中位径を制御して所望の粒子密度の石炭灰を生成させる燃焼工程と、
前記中位径が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記中位径を制御して所望の平均粒子円形度の石炭灰を生成させる燃焼工程と、
前記二段燃焼の際に火炉内の下流側に供給する空気の、前記火炉内に供給する空気の全体に対する割合である二段燃焼率が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記二段燃焼率を制御して所望の粒子円形度の石炭灰を生成させる燃焼工程と、
原料となる石炭の性状により決定される固定炭素と揮発分との比である燃料比が低くなるほど石炭灰の粒径分布が大きくなるという特性に基づき前記燃料比を制御して所望の粒径分布の石炭灰を得る燃焼工程と、
原料となる石炭の性状により決定される酸性率が小さくなるほど石炭灰の粒子平均円形度が高くなるという特性に基づき前記酸性率を制御して所望の粒子形状の石炭灰を生成させる燃焼工程と、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、微粉炭粒径を制御して前記未燃分濃度を調整し、所望のブレーン値の石炭灰を生成させる燃焼工程と、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、前記二段燃焼率を制御して前記未燃分濃度を調整し、所望のブレーン値の石炭灰を生成させる燃焼工程との少なくとも一種類の燃焼工程を有することにより所望の性状の石炭灰を生成させることを特徴とする石炭燃焼方法にある。
本態様によれば、石炭灰の性状を規定する、石炭灰の粒子密度、平均粒子円形度(粒子円形度)、粒径分布、粒子形状またはブレーン値を任意に調整することができる。この結果、用途に応じた最適な石炭灰を有価灰として容易に生成させることができる。
本発明の第2の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
前記微粉炭の中位径が小さくなるほど粒子密度が大きくなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の前記中位径を制御して所望の粒子密度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本態様によれば、生成される石炭灰の粒子密度を考慮して石炭粉砕装置で粉砕される微粉炭の中位径を制御しているので、所望の粒子密度の石炭灰を得ることができる。
本発明の第3の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
質量基準の50%径である微粉炭の中位径が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の前記中位径を制御して所望の粒子平均円形度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本態様によれば、生成される石炭灰の平均粒子円形度を考慮して石炭粉砕装置で粉砕される微粉炭の中位径を制御しているので、所望の平均粒子円形度の石炭灰を得ることができる。
本発明の第4の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の粒径を制御して石炭灰中の未燃分濃度を調整することにより所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本態様によれば、生成される石炭灰のブレーン値を考慮して石炭粉砕装置で粉砕される微粉炭の粒径を制御することにより石炭灰中の未燃分濃度を調整しているので、所望のブレーン値の石炭灰を得ることができる。
本発明の第5の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有するとともに、
前記火炉内に供給する空気の全体に対する割合である二段燃焼率が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記空気量を調整することにより前記二段燃焼率を制御して所望の粒子円形度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本形態によれば、生成される石炭灰の粒子円形度を考慮して二段燃焼率を制御しているので、所望の粒子円形度の石炭灰を得ることができる。
本発明の第6の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有するとともに、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき前記空気量を調整することにより前記火炉内に供給する空気の全体に対する割合である二段燃焼率を制御し、石炭灰中の未燃分濃度を調整することにより所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本形態によれば、生成される石炭灰のブレーン値を考慮して二段燃焼率を制御することにより石炭灰中の未燃分濃度を調整しているので、所望のブレーン値の石炭灰を得ることができる。
本発明の第7の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
原料となる石炭の性状により決定される固定炭素と揮発分との比である燃料比が低くなるほど石炭灰の粒径分布が大きくなるという特性に基づき、前記弁の開度を調整して性状が異なる前記石炭の混合比を調整し、前記石炭の性状により決定される前記燃料比を制御して所望の粒径分布の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本形態によれば、生成される石炭灰の粒径を考慮して性状が異なる石炭の混合比を調整することで燃料費を制御しているので、所望の粒径の石炭灰を得ることができる。
本発明の第8の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
原料となる石炭の性状により決定される酸性率が小さくなるほど石炭灰の粒子平均円形度が高くなるという特性に基づき前記弁の開度を調整して性状が異なる前記石炭の混合比を調整し、前記石炭の性状により決定される酸性率を制御して所望の粒子形状の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本態様によれば、生成される石炭灰の粒子形状を考慮して性状が異なる石炭の混合比を調整することで酸性比を制御しているので、所望の粒子形状の石炭灰を得ることができる。
本発明の第9の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置とを有する一方、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、前記弁の開度を調整して性状が異なる前記石炭の混合比を調整するとともに、前記石炭粉砕装置で粉砕して得る微粉炭の粒径を制御し、石炭灰中の未燃分を調整して所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本形態によれば、生成される石炭灰のブレーン値を考慮して微粉炭の粒径とともに、性状が異なる石炭の混合比も制御しているので、石炭灰中の未燃分濃度をさらに良好に調整して所望のブレーン値の石炭灰を第4の態様の場合よりも、より容易に得ることができる。
本発明の第10の態様は、
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置と、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有する一方、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、
前記弁の開度を調整して性状が異なる前記石炭の混合比を調整するとともに、前記火炉内に供給する空気の全体に対する割合である二段燃焼率を制御し、石炭灰中の未燃分を調整して所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置にある。
本形態によれば、生成される石炭灰のブレーン値を考慮して二段燃焼率とともに、性状が異なる石炭の混合比も制御しているので、石炭灰中の未燃分濃度をさらに良好に調整して所望のブレーン値の石炭灰を第6の態様の場合よりも、より容易に得ることができる。
In order to achieve the above object, the first aspect of the present invention provides:
A coal combustion method having a combustion process in which pulverized coal is mixed with air and burned in two stages in a furnace,
A combustion step of generating coal ash having a desired particle density by controlling the median diameter based on the property that the particle density increases as the median diameter of pulverized coal having a 50% diameter based on mass decreases;
A combustion step of controlling the median diameter based on the characteristic that the average particle circularity increases as the median diameter decreases, thereby generating coal ash having a desired average particle circularity;
Based on the characteristic that the particle average circularity increases as the two-stage combustion rate, which is the ratio of the air supplied to the downstream side of the furnace during the two-stage combustion with respect to the total amount of air supplied into the furnace, decreases. A combustion process for controlling the two-stage combustion rate to produce coal ash having a desired particle circularity;
Desired particle size distribution by controlling the fuel ratio based on the characteristic that the particle size distribution of coal ash increases as the fuel ratio, which is the ratio of fixed carbon to volatile matter determined by the properties of coal as raw material, decreases. A combustion process for obtaining coal ash,
Combustion step of generating coal ash having a desired particle shape by controlling the acidity based on the property that the average circularity of coal ash becomes higher as the acidity determined by the properties of coal as a raw material becomes smaller,
Based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, the combustion step of controlling the pulverized coal particle size to adjust the unburned component concentration and generating coal ash having a desired brane value When,
Based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, the combustion that adjusts the unburned component concentration by controlling the two-stage combustion rate to generate coal ash having a desired brane value. A coal combustion method is characterized in that coal ash having a desired property is generated by having at least one combustion step with the step.
According to this aspect, the particle density, average particle circularity (particle circularity), particle size distribution, particle shape, or brane value of coal ash that defines the properties of coal ash can be arbitrarily adjusted. As a result, the optimal coal ash corresponding to the application can be easily generated as valuable ash.
The second aspect of the present invention is:
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
In order to obtain coal ash having a desired particle density by controlling the median diameter of the pulverized coal obtained by pulverization by the coal pulverizer based on the characteristic that the particle density increases as the median diameter of the pulverized coal decreases. It is in the coal combustion apparatus characterized by comprising.
According to this aspect, since the median diameter of the pulverized coal pulverized by the coal pulverizer is controlled in consideration of the particle density of the generated coal ash, coal ash having a desired particle density can be obtained. .
The third aspect of the present invention is:
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
The median diameter of the pulverized coal obtained by pulverization by the coal pulverizer is controlled based on the property that the average particle circularity becomes higher as the median diameter of the pulverized coal, which is 50% of the mass basis, becomes smaller. The coal combustion apparatus is configured to obtain coal ash having a particle average circularity.
According to this aspect, since the median diameter of the pulverized coal pulverized by the coal pulverizer is controlled in consideration of the average particle circularity of the generated coal ash, the coal ash having a desired average particle circularity is controlled. Can be obtained.
The fourth aspect of the present invention is:
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
Control the particle size of pulverized coal obtained by pulverization with the coal pulverizer based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, thereby adjusting the unburned component concentration in the coal ash. The coal combustion apparatus is configured to obtain coal ash having a desired brane value.
According to this aspect, the unburned matter concentration in the coal ash is adjusted by controlling the particle size of the pulverized coal pulverized by the coal pulverizer in consideration of the brane value of the generated coal ash. Coal ash having a desired brane value can be obtained.
According to a fifth aspect of the present invention,
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having an air nozzle for supplying the inside of the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
The two-stage combustion rate is controlled by adjusting the amount of air based on the characteristic that the particle average circularity increases as the two-stage combustion rate, which is the ratio of the air supplied into the furnace, decreases. A coal combustion apparatus is configured to obtain coal ash having a particle circularity.
According to this embodiment, since the two-stage combustion rate is controlled in consideration of the particle circularity of the produced coal ash, coal ash having a desired particle circularity can be obtained.
The sixth aspect of the present invention is:
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having an air nozzle for supplying the inside of the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
By controlling the amount of air based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases , the two-stage combustion rate, which is the ratio of the total amount of air supplied into the furnace, is controlled, The coal combustion apparatus is configured to obtain coal ash having a desired brane value by adjusting the unburned component concentration in the ash.
According to the present embodiment, the unburned fuel concentration in the coal ash is adjusted by controlling the two-stage combustion rate in consideration of the brane value of the generated coal ash. Can be obtained.
The seventh aspect of the present invention is
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Based on the characteristic that the particle size distribution of coal ash increases as the fuel ratio, which is the ratio of fixed carbon to volatile matter, determined by the properties of the coal as the raw material, decreases, the properties are adjusted by adjusting the opening of the valve. The coal combustion apparatus is configured to adjust the mixing ratio of the different coals and control the fuel ratio determined by the properties of the coal to obtain coal ash having a desired particle size distribution.
According to this embodiment, since the fuel cost is controlled by adjusting the mixing ratio of coal having different properties in consideration of the particle size of the generated coal ash, coal ash having a desired particle size can be obtained. it can.
The eighth aspect of the present invention is
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Adjusting the mixing ratio of the coals with different properties by adjusting the opening of the valve based on the property that the particle average circularity of coal ash increases as the acidity determined by the properties of the coal as the raw material decreases, The coal combustion apparatus is configured to obtain coal ash having a desired particle shape by controlling the acidity determined by the properties of the coal.
According to this aspect, since the acid ratio is controlled by adjusting the mixing ratio of coal having different properties in consideration of the particle shape of the generated coal ash, coal ash having a desired particle shape can be obtained. it can.
The ninth aspect of the present invention provides
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Based on the characteristic that the brane value increases as the unburned matter concentration in the coal ash increases, the opening ratio of the valve is adjusted to adjust the mixing ratio of the coal having different properties, and the coal pulverizer grinds the coal ash. The coal combustion apparatus is configured to control the particle size of pulverized coal obtained to adjust the unburned content in the coal ash to obtain coal ash having a desired brane value.
According to this embodiment, the blending ratio of coal having different properties is controlled together with the particle size of the pulverized coal in consideration of the brane value of the generated coal ash, so that the unburned content concentration in the coal ash is further improved. Thus, coal ash having a desired brane value can be obtained more easily than in the case of the fourth aspect.
The tenth aspect of the present invention provides
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
A coal crusher for producing pulverized coal to be supplied to the furnace by crushing the coal supplied from each hopper via a valve;
While having an air nozzle that feeds into the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
Based on the characteristic that the brane value increases as the unburned matter concentration in coal ash increases,
While adjusting the opening ratio of the valve to adjust the mixing ratio of the coal having different properties , the two-stage combustion rate that is the ratio of the total amount of air supplied into the furnace is controlled, and the unburned content in the coal ash The coal combustion apparatus is configured to obtain coal ash having a desired brain value by adjusting
According to this embodiment, considering the brane value of the generated coal ash, the mixing ratio of coal having different properties is controlled together with the two-stage combustion rate, so the unburned content concentration in the coal ash is further improved. The coal ash having the desired brane value can be adjusted and obtained more easily than in the sixth embodiment.

本発明の石炭燃焼装置及び石炭燃焼方法によれば、微粉炭の燃焼条件や石炭性状を調整することにより必要とする性状の石炭灰を得ることができる石炭燃焼装置となる。従って、石炭灰の基礎的な性状を制御できるので、有価灰として再利用しやすくなる。   According to the coal combustion apparatus and the coal combustion method of the present invention, a coal combustion apparatus capable of obtaining coal ash having the required properties by adjusting the combustion conditions and coal properties of pulverized coal is obtained. Therefore, since the basic property of coal ash can be controlled, it becomes easy to reuse as valuable ash.

図1には本発明の一実施形態例に係る微粉炭燃焼装置の概略系統図を示してある。
図1に示すように、ボイラ火炉2の周囲にバーナ3が複数個設けられ、バーナ3は微粉炭路11を介して微粉炭製造装置8と繋がっている。図1にはボイラ火炉2の左右それぞれにバーナ3を3個ずつ示した。微粉炭製造装置8には石炭を貯留するホッパ9が複数個あり、各ホッパには燃料比(石炭の質)や酸性率(石炭の質)が異なる石炭を投入する。
FIG. 1 shows a schematic system diagram of a pulverized coal combustion apparatus according to an embodiment of the present invention.
As shown in FIG. 1, a plurality of burners 3 are provided around the boiler furnace 2, and the burners 3 are connected to a pulverized coal production apparatus 8 through a pulverized coal passage 11. In FIG. 1, three burners 3 are shown on each of the left and right sides of the boiler furnace 2. The pulverized coal production apparatus 8 has a plurality of hoppers 9 for storing coal, and coal having different fuel ratio (coal quality) and acidity (coal quality) is fed into each hopper.

図1にはそれぞれのホッパを9a、9b、9cとして3個示した。各ホッパ9a、9b、9cの排出口には流量を調整する手段である弁10a、10b、10cがあり弁10a、10b、10cを介して各ホッパ9a、9b、9cは石炭粉砕装置10に繋がっている。微粉炭製造装置8のそれぞれのホッパ9a、9b、9cに、燃料比や酸性率の異なる石炭を投入する。   FIG. 1 shows three hoppers 9a, 9b and 9c. The discharge ports of the hoppers 9a, 9b and 9c have valves 10a, 10b and 10c which are means for adjusting the flow rate, and the hoppers 9a, 9b and 9c are connected to the coal crusher 10 via the valves 10a, 10b and 10c. ing. Coal having a different fuel ratio and acidity is introduced into each hopper 9a, 9b, 9c of the pulverized coal production apparatus 8.

ホッパに投入する石炭は1種類だけでも構わないし、ホッパに投入する石炭の質は燃料比だけに注目しても構わないし、または酸性率だけに注目しても構わない。   Only one type of coal may be input to the hopper, and the quality of the coal input to the hopper may be focused only on the fuel ratio, or only on the acidity.

例えば、ホッパ9aには燃料比と酸性率の高い石炭を投入し、9bには燃料比と酸性率の低い石炭を投入し、9cには燃料比が高く、酸性率の低い石炭を投入すると、石炭の量を調整する手段である弁10a、10b、10cがホッパ9a、9b、9cに投入された石炭の流量を調整し所望の混合割合と所望の量の石炭が石炭粉砕装置10へと運ばれる。そして所望の混合割合でかつ所望量の石炭は石炭粉砕装置10で、所望の粒径に調整されながら粉砕され微粉炭になる。   For example, when coal with a high fuel ratio and low acidity is introduced into hopper 9a, coal with low fuel ratio and low acidity is introduced into 9b, and coal with high fuel ratio and low acidity is introduced into 9c, Valves 10a, 10b, and 10c, which are means for adjusting the amount of coal, adjust the flow rate of coal charged into the hoppers 9a, 9b, and 9c, and a desired mixing ratio and a desired amount of coal are conveyed to the coal crusher 10. It is. Then, a desired amount of coal and a desired amount of coal are pulverized by the coal pulverizer 10 while being adjusted to a desired particle size to become pulverized coal.

このように燃料比や酸性率や粒径が調整された微粉炭は微粉炭路11を通り、ボイラ火炉2の周囲にある複数個あるバーナ3からボイラ火炉2に入り燃焼する。一方、ボイラ火炉2には、例えば、バーナ3を通して空気が送り込まれている。空気は、空気制御装置7(空気導入制御手段)から空気路6を介してボイラ火炉2の周囲にある複数個あるバーナ3と上段空気ノズル4(後段空気導入手段)からボイラ火炉2の中に入る。図1には空気が送り込まれる様子をボイラ火炉2の周囲にある左右のバーナ3付近に左右それぞれ3本矢印で示した。また、上段空気ノズル4をボイラ火炉2の周囲に左右1個ずつ示した。   The pulverized coal whose fuel ratio, acidity, and particle size are adjusted in this way passes through the pulverized coal passage 11 and enters the boiler furnace 2 through a plurality of burners 3 around the boiler furnace 2 and burns. On the other hand, air is sent to the boiler furnace 2 through a burner 3, for example. The air enters the boiler furnace 2 from a plurality of burners 3 around the boiler furnace 2 and the upper air nozzle 4 (rear air introduction means) through the air path 6 from the air control device 7 (air introduction control means). enter. In FIG. 1, the state in which air is sent is indicated by three arrows on the left and right sides in the vicinity of the left and right burners 3 around the boiler furnace 2. Further, one upper air nozzle 4 is shown around the boiler furnace 2 on the left and right sides.

微粉炭の燃焼雰囲気に後段空気を導入することを、二段燃焼と呼び、後から導入する後段空気量の割合を二段燃焼率として表すが、ここでの後段空気とは図1の上段空気ノズル4(後段空気導入手段)から入る空気のことであり、上段空気ノズル4から入る空気量の割合である二段燃焼率は、空気量を調整する空気弁5(後段空気導入手段)で調整される。   The introduction of the latter stage air into the pulverized coal combustion atmosphere is called the second stage combustion, and the ratio of the latter stage air amount introduced later is expressed as the second stage combustion rate. Here, the latter stage air is the upper stage air in FIG. Air entering from the nozzle 4 (rear air introduction means), and the two-stage combustion rate, which is the ratio of the air amount entering from the upper air nozzle 4, is adjusted by the air valve 5 (rear air introduction means) for adjusting the air amount. Is done.

このようにして空気制御装置7(空気導入制御手段)から出た空気は空気路6を通り、下段にあるバーナ3(矢印で示した)からボイラ火炉2の中へと送り込まれ、空気弁5が二段燃焼率を制御することにより、上段空気ノズル4(後段空気導入手段)から流量を調整された空気がボイラ火炉2に送り込まれる。これによって微粉炭がボイラ火炉2の中で完全燃焼する。やがてボイラ火炉2の中で燃焼した微粉炭は、灰となりボイラ1の右上方部と下部にある石炭灰排出口12から排出される。   In this way, the air emitted from the air control device 7 (air introduction control means) passes through the air passage 6 and is sent into the boiler furnace 2 from the lower burner 3 (indicated by the arrow), and the air valve 5 However, by controlling the two-stage combustion rate, the air whose flow rate is adjusted is sent from the upper air nozzle 4 (rear air introduction means) to the boiler furnace 2. As a result, the pulverized coal is completely burned in the boiler furnace 2. Eventually, the pulverized coal burned in the boiler furnace 2 becomes ash and is discharged from the coal ash discharge ports 12 at the upper right and lower portions of the boiler 1.

以上のように、石炭は微粉炭製造装置8で燃料比と酸性率を制御され、所望の混合割合、すなわち所望の質の石炭になる。そして、所望の質の石炭は石炭粉砕装置10で粒径を調整されて所望の粒径の微粉炭となり、バーナ3に送られる。微粉炭はバーナ3の空気と混合して燃焼する。そして、空気制御装置7(空気導入制御手段)では後から入れる空気の割合である二段燃焼率が空気弁5で制御され、上段空気ノズル4から更に所望量の空気が送り込まれ、微粉炭はボイラ火炉2で燃焼する。完全燃焼した生成灰はボイラ1から石炭灰排出口12へと排出される。石炭の質を制御すると共に燃焼条件である二段燃焼率を制御することにより、排出された生成灰の基礎的性状が任意に調整される。   As described above, the coal is controlled in the fuel ratio and the acidity by the pulverized coal production apparatus 8 and becomes a coal having a desired mixing ratio, that is, a desired quality. The desired quality coal is adjusted in particle size by the coal crusher 10 to become pulverized coal having a desired particle size, and is sent to the burner 3. The pulverized coal is mixed with the air of the burner 3 and burned. In the air control device 7 (air introduction control means), the two-stage combustion rate, which is the ratio of air to be introduced later, is controlled by the air valve 5, and a desired amount of air is further fed from the upper air nozzle 4, and the pulverized coal is It burns in the boiler furnace 2. The completely burned product ash is discharged from the boiler 1 to the coal ash discharge port 12. By controlling the quality of coal and controlling the two-stage combustion rate, which is a combustion condition, the basic properties of the generated ash discharged are arbitrarily adjusted.

図1では微粉炭の燃焼条件と質の制御により、排出される石炭灰を所望の灰の粒子として調整可能である過程を図示した。この過程には、微粉炭の燃焼条件と質を表すパラメータと生成した石炭灰の粒子の基礎的性状を表すパラメータがある。それらのパラメータを用いて本発明の石炭燃焼装置において微粉炭の制御による所望の基礎的性状を有する灰の調整方法を図2〜図6に基づいて説明する。   FIG. 1 illustrates a process in which discharged coal ash can be adjusted as desired ash particles by controlling the combustion conditions and quality of pulverized coal. In this process, there are parameters indicating the combustion conditions and quality of pulverized coal and parameters indicating the basic properties of the generated coal ash particles. The adjustment method of the ash which has the desired fundamental property by control of pulverized coal in the coal combustion apparatus of this invention using these parameters is demonstrated based on FIGS.

図2では本発明の石炭燃焼装置におけるパラメータ概念図を示す。図3では、微粉炭中位径に対する石炭灰の粒子密度と粒子平均円形度との関係を、図4では、二段燃焼率と石炭灰の粒子平均円形度との関係を、図5では、燃料比と粒径分布の広がり度合との関係を、図6では酸性率と石炭灰の粒子平均円形度との関係を示す。   In FIG. 2, the parameter conceptual diagram in the coal combustion apparatus of this invention is shown. 3, the relationship between the particle density of coal ash and the average particle circularity with respect to the median diameter of pulverized coal, FIG. 4 illustrates the relationship between the two-stage combustion rate and the particle average circularity of coal ash, and FIG. FIG. 6 shows the relationship between the fuel ratio and the degree of spread of the particle size distribution, and FIG. 6 shows the relationship between the acid ratio and the average particle circularity of coal ash.

図2に示すように、本発明での概念として制御するパラメータと制御された結果得られる灰の粒子の性状を表すパラメータとを明記した。本発明での、制御するパラメータとして大きく分けると二つあり、条件と質である。条件とは燃焼条件のことであり、微粉炭粒径と上段の方の空気口である上段空気ノズル4から入れる空気量の割合を示す二段燃焼率が挙げられ、石炭の質としては固定炭素と揮発分の比である燃料比と石炭の溶融性の指標である酸性率が挙げられる。さらに制御する石炭の燃焼条件や質のパラメータに対して、具体的に石炭燃焼装置の概略系統図である図1のどの部分で制御されるかを示すと、石炭の燃焼条件として微粉炭粒径は図1の石炭粉砕装置10で制御され、途中から入れる空気量の割合を示す二段燃焼率は図1の空気弁5で調整される。また、使用する石炭の質として固定炭素と揮発分の比である燃料比や石炭の溶融性の指標となる酸性率は図1の複数個あるホッパ9の混合割合を調整する弁10a、10b、10cを備えた微粉炭製造装置8で制御される。   As shown in FIG. 2, parameters to be controlled as a concept in the present invention and parameters representing properties of ash particles obtained as a result of the control are specified. In the present invention, the parameters to be controlled are roughly divided into two, ie, conditions and quality. The conditions are combustion conditions, and include a two-stage combustion rate that indicates the ratio of the pulverized coal particle size and the amount of air introduced from the upper air nozzle 4 that is the upper air port, and the quality of coal is fixed carbon. And fuel ratio, which is the ratio of volatile matter, and acidity, which is an indicator of coal meltability. Furthermore, with respect to the combustion conditions and quality parameters of the coal to be controlled, it is specifically shown in FIG. 1 which is a schematic system diagram of the coal combustion apparatus, the pulverized coal particle size as the coal combustion conditions. Is controlled by the coal crusher 10 of FIG. 1, and the two-stage combustion rate indicating the ratio of the amount of air introduced from the middle is adjusted by the air valve 5 of FIG. Further, as the quality of coal to be used, the ratio of fixed carbon to the volatile component, the fuel ratio, and the acid ratio that is an indicator of coal meltability are valves 10a, 10b for adjusting the mixing ratio of the plurality of hoppers 9 in FIG. It is controlled by the pulverized coal production apparatus 8 provided with 10c.

以上をまとめると、制御するパラメータとして燃焼条件は、微粉炭粒径と二段燃焼率があり、石炭の質は、燃料比と酸性率がある。そして石炭の燃焼条件である微粉炭粒径は図1の石炭粉砕装置10で制御され、二段燃焼率は図1の空気弁5で制御され、石炭の質である燃料比と酸性率は図1の微粉炭製造装置8で制御される。   In summary, combustion parameters include pulverized coal particle size and two-stage combustion rate as parameters to be controlled, and coal quality includes fuel ratio and acidity rate. The pulverized coal particle size, which is the coal combustion condition, is controlled by the coal crusher 10 in FIG. 1, the two-stage combustion rate is controlled by the air valve 5 in FIG. 1, and the fuel ratio and acidity, which are the quality of coal, are shown in FIG. 1 pulverized coal production apparatus 8.

上記のような石炭の燃焼条件や質で制御され燃焼した微粉炭が図1の石炭灰排出口12から石炭灰として排出されるのであるが、この排出される石炭灰の性状が所望の基礎的性状を持つように調整される。排出される石炭灰の基礎的性状についてもパラメータとして表記すると、灰の性状のパラメータは、粒径分布や比表面積の指標であるブレーン値、粒子の密度、粒子の形状そして粒子の円形度である。円形度とは、粒子の形状を表す指標であり、真円の場合1に、形状が歪になるに従い0に漸近する。   The pulverized coal that has been controlled and burned according to the combustion conditions and quality of coal as described above is discharged as coal ash from the coal ash outlet 12 in FIG. 1, and the properties of the discharged coal ash are desired to be fundamental. Adjusted to have properties. The basic properties of the discharged coal ash are also expressed as parameters. The parameters of the ash properties are the brane value, particle density, particle shape, and particle circularity, which are indicators of particle size distribution and specific surface area. . The degree of circularity is an index representing the shape of a particle, and asymptotically approaches 1 when the shape is a perfect circle and becomes 0 as the shape becomes distorted.

以上のように本発明では石炭の燃焼条件と質を制御(制御するパラメータは微粉炭粒径、二段燃焼率、燃料比、酸性率)することにより、必要とする基礎的性状(制御された結果得られる灰の性状を表すパラメータは粒径分布、ブレーン値、粒子密度、粒子形状、粒子円形度)の石炭灰が得られるのである。   As described above, in the present invention, the basic properties (controlled) are controlled by controlling the combustion conditions and quality of coal (control parameters are pulverized coal particle size, two-stage combustion rate, fuel ratio, acidity rate). The parameters representing the properties of the resulting ash are coal ash having a particle size distribution, brane value, particle density, particle shape, particle circularity).

制御するパラメータと制御された結果得られる石炭灰の性状を表すパラメータとがあることを図2で示したが、制御するパラメータとその結果得られた石炭灰の基礎的性状のパラメータとの間には相関が有り、それらのパラメータ間の相関関係を具体的に図3〜図6で示しながら石炭灰の調整方法について説明する。   FIG. 2 shows that there are parameters to be controlled and parameters representing the properties of the coal ash obtained as a result of the control. Between the parameters to be controlled and the parameters of the basic properties of the resulting coal ash, There is a correlation, and a method for adjusting coal ash will be described while specifically showing the correlation between these parameters in FIGS.

図3には投入される微粉炭の中位径に対して排出された石炭灰の粒子密度[g/cm]と粒子平均円形度を示す。中位径とは質量基準の50%径のことである。そして、横軸が微粉炭中位径[μm]で縦軸が灰の粒子密度[g/cm]と灰の粒子平均円形度である。図3に示すように中位径が小さいと、密度は大きく、中位径が大きいと密度は小さくなる。微粉炭が細かいほど燃焼が速やかに進行し、灰分粒子の昇温・溶融が促進するため微粉炭を細かくすると排出される石炭灰の粒子の密度を増大させることができ、灰粒子の粒形を円くすることができる。このように、微粉炭の中位径を制御することにより所望の密度と平均円形度の石炭灰の粒子を得ることができる。 FIG. 3 shows the particle density [g / cm 3 ] and the average particle circularity of the discharged coal ash with respect to the median diameter of the pulverized coal to be input. The median diameter is a 50% diameter based on mass. The horizontal axis is the pulverized coal median diameter [μm], and the vertical axis is the ash particle density [g / cm 3 ] and the ash particle average circularity. As shown in FIG. 3, when the median diameter is small, the density is large, and when the median diameter is large, the density is small. The finer the pulverized coal, the faster the combustion proceeds, and the temperature rise / melting of the ash particles accelerates, so finer pulverized coal can increase the density of the discharged coal ash particles, Can be rounded. In this way, particles of coal ash having a desired density and average circularity can be obtained by controlling the median diameter of pulverized coal.

図4には二段燃焼率[%]と排出された石炭灰の粒子平均円形度との関係を示す。二段燃焼率とは、後から導入する後段空気量の割合のことであり、図1では空気弁5で調整され上段空気ノズル4(後段空気導入手段)から送り込まれる空気量の割合である。横軸が二段燃焼率[%]で縦軸が石炭灰の粒子の形状である。   FIG. 4 shows the relationship between the two-stage combustion rate [%] and the particle average circularity of the discharged coal ash. The two-stage combustion rate is the ratio of the subsequent air amount introduced later, and is the ratio of the air amount that is adjusted by the air valve 5 and fed from the upper air nozzle 4 (rear air introducing means) in FIG. The horizontal axis represents the two-stage combustion rate [%], and the vertical axis represents the shape of the coal ash particles.

途中から入れる空気の量の割合を示す二段燃焼率を増加した場合、不定形になりやすい未燃分等が増大するので、粒子の円形度を低下させることができる。このように、燃焼条件である二段燃焼率を制御することにより所望の円形度の灰粒子を得ることができる。   When the two-stage combustion rate indicating the ratio of the amount of air introduced from the middle is increased, the unburned portion that tends to be indefinite increases, so the circularity of the particles can be reduced. In this way, ash particles with a desired circularity can be obtained by controlling the two-stage combustion rate, which is a combustion condition.

図5には燃料比(石炭の質)と排出された石炭灰の粒径分布の広がり度合との関係を示す。燃料比とは固定炭素と揮発分の比である。   FIG. 5 shows the relationship between the fuel ratio (coal quality) and the extent of the particle size distribution of the discharged coal ash. The fuel ratio is the ratio of fixed carbon to volatile content.

微粉炭がボイラ火炉2の中で、固定炭素と灰分などの混合物となり粒子状固形物として燃焼しているが、微粉炭中の揮発分が放出し、その粒子状固形物の分裂が促進されるため、燃料比を小さくすると、石炭灰の粒径分布の幅が広がり小粒径の粒子量を増大することができる。このように、固定炭素と揮発分のである燃料比を制御することにより所望の石炭灰の粒径を得ることができる。
The pulverized coal becomes a mixture of fixed carbon and ash in the boiler furnace 2 and burns as a particulate solid, but the volatile matter in the pulverized coal is released and the fragmentation of the particulate solid is promoted. Therefore, when the fuel ratio is reduced, the width of the coal ash particle size distribution is widened, and the amount of particles having a small particle size can be increased. Thus, the desired coal ash particle size can be obtained by controlling the fuel ratio, which is the ratio of fixed carbon to volatile matter.

図6には微粉炭の酸性率[%](石炭の質)と排出された石炭灰の粒子平均円形度との関係を示す。酸性率とは、灰分の溶融性の指標である。   FIG. 6 shows the relationship between the acidity [%] of pulverized coal (coal quality) and the particle average circularity of discharged coal ash. The acidity is an index of the meltability of ash.

酸性率を小さくすると灰分粒子が溶融しやすくなるので、粒子平均円形度を向上させ球状に近づけることができるので、図6のように酸性率を小さくすると円形度を増大させることができ、酸性率を大きくすると、円形度を減少させることができる。このように灰分の溶融性の指標である酸性率を制御することにより所望の石炭灰の粒子形状を得ることができる。   If the acidity is reduced, the ash particles are likely to melt, so that the particle average circularity can be improved to approximate a spherical shape. Therefore, if the acidity is reduced as shown in FIG. 6, the circularity can be increased. Increasing the can reduce the circularity. Thus, the desired coal ash particle shape can be obtained by controlling the acidity, which is an indicator of the meltability of ash.

図7には、石炭灰中の未燃分濃度[%]とブレーン値との関係を示す。石炭灰粒子のブレーン値は石炭灰粒子の比表面積である。   FIG. 7 shows the relationship between the unburned component concentration [%] in the coal ash and the brane value. The brane value of coal ash particles is the specific surface area of coal ash particles.

石炭性状や燃焼条件を変えると、石炭灰中の未燃分量も変わるので、石炭灰中の未燃分濃度を調整することによってブレーン値を制御することができる。石炭灰粒子を十分に燃焼させると、石炭灰中の未燃分濃度は減少し、溶融が進むので比表面積を減らすことができる。燃焼が不十分だと、石炭中の未燃分濃度は増加し、溶融があまり進まないので比表面積を大きくすることができる。従って、図7のように石炭灰中の未燃分濃度を小さくするとブレーン値を小さくすることができ、石炭灰中の未燃分濃度を大きくすると、ブレーン値を大きくすることができる。このように、石炭灰中の未燃分濃度を制御することにより所望の灰のブレーン値を得ることができる。   When the coal properties and combustion conditions are changed, the amount of unburned coal in coal ash also changes, so that the brane value can be controlled by adjusting the concentration of unburned coal in coal ash. When the coal ash particles are sufficiently burned, the unburned component concentration in the coal ash decreases and the specific surface area can be reduced because melting proceeds. If the combustion is insufficient, the unburned component concentration in the coal increases and the melting does not progress so much, so that the specific surface area can be increased. Therefore, as shown in FIG. 7, when the unburned component concentration in the coal ash is decreased, the brane value can be decreased, and when the unburned component concentration in the coal ash is increased, the brane value can be increased. In this way, the desired ash brane value can be obtained by controlling the unburned component concentration in the coal ash.

以上のように本発明での石炭燃焼装置では、石炭の燃焼状況と質を制御することにより所望の石炭灰の性状を得ることができる。   As described above, in the coal combustion apparatus according to the present invention, desired properties of coal ash can be obtained by controlling the combustion state and quality of coal.

また、本発明を図示の実施形態について説明したが、本発明はかかる実施の形態に限定されず、本発明の範囲内でその具体的構造に種々の変更を加えて良いことは言うまでもない。   Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to such embodiments, and it goes without saying that various modifications may be made to the specific structure within the scope of the present invention.

上記をまとめると本発明での石炭燃焼装置の燃焼状況調整手段としては、空気導入制御手段(空気制御装置7)と後段空気導入手段(上段空気ノズル4、空気弁5)である。あるいは、本発明での石炭の燃焼装置の燃焼状況調整手段は、微粉炭の粒度を調整する粒度調整手段(石炭粉砕装置10)である。あるいは、本発明での石炭の燃焼状況調整手段は、空気導入制御手段(空気制御装置7)と後段空気導入手段(上段空気ノズル4、空気弁5)と微粉炭の粒度を調整する粒度調整手段(石炭粉砕装置10)とを備えている。そして、本発明での石炭燃焼装置の質調整手段(微粉炭製造装置8)として、石炭の質は固定炭素と揮発分の比である燃料比である。あるいは、本発明での石炭燃焼装置の質調整手段(微粉炭製造装置8)として、石炭の質は灰分の溶融性の指標である酸性率である。あるいは、本発明での石炭燃焼装置の質調整手段(微粉炭製造装置8)として、石炭の質は固定炭素と揮発分の比である燃料比と灰分の溶融性の指標である酸性率である。   In summary, the combustion condition adjusting means of the coal combustion apparatus according to the present invention includes air introduction control means (air control device 7) and rear stage air introduction means (upper stage air nozzle 4, air valve 5). Or the combustion condition adjustment means of the coal combustion apparatus in this invention is a particle size adjustment means (coal crushing apparatus 10) which adjusts the particle size of pulverized coal. Alternatively, the coal combustion state adjusting means in the present invention includes air introduction control means (air control device 7), rear air introduction means (upper air nozzle 4, air valve 5), and particle size adjustment means for adjusting the particle size of pulverized coal. (Coal crusher 10). And as a quality adjustment means (pulverized coal manufacturing apparatus 8) of the coal combustion apparatus in this invention, the quality of coal is a fuel ratio which is ratio of fixed carbon and volatile matter. Alternatively, as the quality adjusting means (pulverized coal production device 8) of the coal combustion apparatus according to the present invention, the quality of the coal is an acid rate that is an index of meltability of ash. Alternatively, as the quality adjusting means (pulverized coal production device 8) of the coal combustion apparatus according to the present invention, the quality of coal is a fuel ratio which is a ratio of fixed carbon to volatile matter and an acidity which is an index of meltability of ash. .

本発明の石炭燃焼装置は、微粉炭の燃焼条件や質を制御することで火炉から排出される石炭灰を所望の性状の灰として得ることができる。このため、生成した石炭灰をセメント混和材等に利用できる。   The coal combustion apparatus of the present invention can obtain coal ash discharged from a furnace as ash having a desired property by controlling the combustion conditions and quality of pulverized coal. For this reason, the produced coal ash can be used as a cement admixture or the like.

例えば、石炭灰をコンクリート混和材等へ利用する際には、コンクリートの流動性等に留意する必要がある。石炭灰の密度が高くなると、相対的にコンクリート中に占める水の体積が増加し、流動性が増す。また、石炭灰の形状が円形化すると、粒子同士の摩擦が減り流動性が向上する。   For example, when using coal ash as a concrete admixture, it is necessary to pay attention to the fluidity of concrete. When the density of coal ash increases, the volume of water in the concrete increases relatively, and the fluidity increases. Moreover, when the shape of coal ash is rounded, friction between particles is reduced and fluidity is improved.

このようにして、石炭灰の性状を制御することにより、コンクリート混和材への利用が高められる。   Thus, the utilization to a concrete admixture is improved by controlling the property of coal ash.

また、色々な性状の所望の灰を作りだすことができるため良質のセメント原料または道路路盤材、地盤改良材、土木工事用、人工軽量骨材、焼成材、焼成人工骨材、焼成タイル・れんが、建材ボード用、そして埋め立て材や雪道等の滑り止め材等それらの関連する産業分野で幅広く利用することができる。   In addition, because it can produce the desired ash of various properties, high-quality cement raw materials or road roadbed materials, ground improvement materials, civil engineering work, artificial lightweight aggregates, fired materials, fired artificial aggregates, fired tiles and bricks, It can be widely used in building related boards and in related industrial fields such as landfill materials and anti-slip materials such as snowy roads.

本発明は微粉炭の燃焼条件と質を調整し、排出される灰の性状を制御する石炭燃焼装置と石炭燃焼装置に関し、蒸気を生成するボイラの産業分野で利用することができる。   The present invention relates to a coal combustion device and a coal combustion device that adjust the combustion conditions and quality of pulverized coal and control the properties of discharged ash, and can be used in the industrial field of boilers that generate steam.

本発明の石炭燃焼装置の概略系統図である。It is a schematic system diagram of the coal combustion apparatus of the present invention. 本発明の石炭燃焼装置におけるパラメータ概念図である。It is a parameter conceptual diagram in the coal combustion apparatus of this invention. 微粉炭中位径に対する石炭灰の粒子密度と粒子平均円形度との関係図である。It is a relationship figure of the particle density of coal ash with respect to the pulverized coal median diameter, and particle average circularity. 二段燃焼率と石炭灰の粒子平均円形度との関係図である。It is a relationship figure of a two-stage combustion rate and the particle average circularity of coal ash. 燃料比と粒径分布の広がり度合との関係図である。FIG. 4 is a relationship diagram between a fuel ratio and a degree of spread of a particle size distribution. 酸性率と石炭灰の粒子平均円形度との関係図である。It is a related figure of the acidity and the particle average circularity of coal ash. 灰中未燃分濃度とブレーン値との関係図である。It is a related figure of unburned matter concentration in ash and brane value.

符号の説明Explanation of symbols

1 ボイラ
2 ボイラ火炉
3 バーナ
4 上段空気ノズル
5 空気弁
6 空気路
7 空気制御装置
8 微粉炭製造装置
9、9a、9b、9c ホッパ
10 石炭粉砕装置
10a、10b、10c 弁
11 微粉炭路
12 石炭灰排出口

DESCRIPTION OF SYMBOLS 1 Boiler 2 Boiler furnace 3 Burner 4 Upper stage air nozzle 5 Air valve 6 Air path 7 Air control apparatus 8 Pulverized coal production apparatus 9, 9a, 9b, 9c Hopper 10 Coal crushing apparatus 10a, 10b, 10c Valve 11 Pulverized coal path 12 Coal Ash outlet

Claims (10)

微粉炭を空気と混合させて火炉内で二段燃焼させる燃焼工程を有する石炭燃焼方法であって、
質量基準の50%径である微粉炭の中位径が小さくなるほど粒子密度が大きくなるという特性に基づき前記中位径を制御して所望の粒子密度の石炭灰を生成させる燃焼工程と、
前記中位径が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記中位径を制御して所望の粒子平均円形度の石炭灰を生成させる燃焼工程と、
前記二段燃焼の際に火炉内の下流側に供給する空気の、前記火炉内に供給する空気の全体に対する割合である二段燃焼率が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記二段燃焼率を制御して所望の粒子円形度の石炭灰を生成させる燃焼工程と、
原料となる石炭の性状により決定される固定炭素と揮発分との比である燃料比が低くなるほど石炭灰の粒径分布が大きくなるという特性に基づき前記燃料比を制御して所望の粒径分布の石炭灰を得る燃焼工程と、
原料となる石炭の性状により決定される酸性率が小さくなるほど石炭灰の粒子平均円形度が高くなるという特性に基づき前記酸性率を制御して所望の粒子形状の石炭灰を生成させる燃焼工程と、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、微粉炭粒径を制御して前記未燃分濃度を調整し、所望のブレーン値の石炭灰を生成させる燃焼工程と、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、前記二段燃焼率を制御して前記未燃分濃度を調整し、所望のブレーン値の石炭灰を生成させる燃焼工程との少なくとも一種類の燃焼工程を有することにより所望の性状の石炭灰を生成させることを特徴とする石炭燃焼方法。
A coal combustion method having a combustion process in which pulverized coal is mixed with air and burned in two stages in a furnace,
A combustion step of generating coal ash having a desired particle density by controlling the median diameter based on the property that the particle density increases as the median diameter of pulverized coal having a 50% diameter based on mass decreases;
A combustion step of generating coal ash having a desired particle average circularity by controlling the median diameter based on the property that the particle average circularity increases as the median diameter decreases;
Based on the characteristic that the particle average circularity increases as the two-stage combustion rate, which is the ratio of the air supplied to the downstream side of the furnace during the two-stage combustion with respect to the total amount of air supplied into the furnace, decreases. A combustion process for controlling the two-stage combustion rate to produce coal ash having a desired particle circularity;
Desired particle size distribution by controlling the fuel ratio based on the characteristic that the particle size distribution of coal ash increases as the fuel ratio, which is the ratio of fixed carbon to volatile matter determined by the properties of coal as raw material, decreases. A combustion process for obtaining coal ash,
Combustion step of generating coal ash having a desired particle shape by controlling the acidity based on the property that the average circularity of coal ash becomes higher as the acidity determined by the properties of coal as a raw material becomes smaller,
Based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, the combustion step of controlling the pulverized coal particle size to adjust the unburned component concentration and generating coal ash having a desired brane value When,
Based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, the combustion that adjusts the unburned component concentration by controlling the two-stage combustion rate to generate coal ash having a desired brane value. A coal combustion method comprising generating coal ash having a desired property by having at least one kind of combustion step with the step.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
前記微粉炭の中位径が小さくなるほど粒子密度が大きくなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の前記中位径を制御して所望の粒子密度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
In order to obtain coal ash having a desired particle density by controlling the median diameter of the pulverized coal obtained by pulverization by the coal pulverizer based on the characteristic that the particle density increases as the median diameter of the pulverized coal decreases. A coal combustion apparatus characterized by comprising.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
質量基準の50%径である微粉炭の中位径が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の前記中位径を制御して所望の粒子平均円形度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
The median diameter of the pulverized coal obtained by pulverization by the coal pulverizer is controlled based on the property that the average particle circularity becomes higher as the median diameter of the pulverized coal, which is 50% of the mass basis, becomes smaller. A coal combustion apparatus configured to obtain coal ash having a particle average circularity.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
原料となる石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき前記石炭粉砕装置で粉砕して得る微粉炭の粒径を制御して石炭灰中の未燃分濃度を調整することにより所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing the raw coal,
Control the particle size of pulverized coal obtained by pulverization with the coal pulverizer based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases, thereby adjusting the unburned component concentration in the coal ash. A coal combustion apparatus configured to obtain coal ash having a desired brane value.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有するとともに、
前記火炉内に供給する空気の全体に対する割合である二段燃焼率が小さくなるほど粒子平均円形度が高くなるという特性に基づき前記空気量を調整することにより前記二段燃焼率を制御して所望の粒子円形度の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having an air nozzle for supplying the inside of the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
The two-stage combustion rate is controlled by adjusting the amount of air based on the characteristic that the particle average circularity increases as the two-stage combustion rate, which is the ratio of the air supplied into the furnace, decreases. A coal combustion apparatus configured to obtain coal ash having a particle circularity.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有するとともに、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき前記空気量を調整することにより前記火炉内に供給する空気の全体に対する割合である二段燃焼率を制御し、石炭灰中の未燃分濃度を調整することにより所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
While having an air nozzle for supplying the inside of the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
By controlling the amount of air based on the characteristic that the brane value increases as the unburned component concentration in the coal ash increases , the two-stage combustion rate, which is the ratio of the total amount of air supplied into the furnace, is controlled, A coal combustion apparatus configured to obtain coal ash having a desired brane value by adjusting an unburned component concentration in the ash.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
原料となる石炭の性状により決定される固定炭素と揮発分との比である燃料比が低くなるほど石炭灰の粒径分布が大きくなるという特性に基づき、前記弁の開度を調整して性状が異なる前記石炭の混合比を調整し、前記石炭の性状により決定される前記燃料比を制御して所望の粒径分布の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Based on the characteristic that the particle size distribution of coal ash increases as the fuel ratio, which is the ratio of fixed carbon to volatile matter, determined by the properties of the coal as the raw material, decreases, the properties are adjusted by adjusting the opening of the valve. A coal combustion apparatus configured to adjust the mixing ratio of the different coals and control the fuel ratio determined by the properties of the coal to obtain coal ash having a desired particle size distribution.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置を有するとともに、
原料となる石炭の性状により決定される酸性率が小さくなるほど石炭灰の粒子平均円形度が高くなるという特性に基づき前記弁の開度を調整して性状が異なる前記石炭の混合比を調整し、前記石炭の性状により決定される酸性率を制御して所望の粒子形状の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Adjusting the mixing ratio of the coals with different properties by adjusting the opening of the valve based on the property that the particle average circularity of coal ash increases as the acidity determined by the properties of the coal as the raw material decreases, A coal combustion apparatus configured to obtain a coal ash having a desired particle shape by controlling an acidity determined by the properties of the coal.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置とを有する一方、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、前記弁の開度を調整して性状が異なる前記石炭の混合比を調整するとともに、前記石炭粉砕装置で粉砕して得る微粉炭の粒径を制御し、石炭灰中の未燃分を調整して所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
While having a coal pulverizer for producing pulverized coal to be supplied to the furnace by pulverizing coal supplied from each hopper via a valve,
Based on the characteristic that the brane value increases as the unburned matter concentration in the coal ash increases, the opening ratio of the valve is adjusted to adjust the mixing ratio of the coal having different properties, and the coal pulverizer grinds the coal ash. A coal combustion apparatus configured to control the particle diameter of pulverized coal obtained in the above and adjust the unburned content in the coal ash to obtain coal ash having a desired brane value.
微粉炭を空気と混合させて燃焼させる火炉を備える石炭燃焼装置であって、
性状が異なる石炭を同種の性状の石炭毎に貯留する複数のホッパと、
弁を介して前記各ホッパから供給される石炭を粉砕することにより前記火炉に供給する微粉炭を製造する石炭粉砕装置と、
前記火炉の下流側で微粉炭をさらに燃焼させる二段燃焼用の空気量を空気弁で調整しつつ前記火炉内に供給する空気ノズルを有する一方、
石炭灰中の未燃分濃度が大きくなるほどブレーン値が大きくなるという特性に基づき、
前記弁の開度を調整して性状が異なる前記石炭の混合比を調整するとともに、前記火炉内に供給する空気の全体に対する割合である二段燃焼率を制御し、石炭灰中の未燃分を調整して所望のブレーン値の石炭灰を得るように構成したことを特徴とする石炭燃焼装置。
A coal combustion apparatus comprising a furnace for burning pulverized coal mixed with air,
A plurality of hoppers that store coal of different properties for each type of coal of the same type;
A coal crusher for producing pulverized coal to be supplied to the furnace by crushing the coal supplied from each hopper via a valve;
While having an air nozzle that feeds into the furnace while adjusting the amount of air for two-stage combustion that further burns pulverized coal on the downstream side of the furnace with an air valve,
Based on the characteristic that the brane value increases as the unburned matter concentration in coal ash increases,
While adjusting the opening ratio of the valve to adjust the mixing ratio of the coal having different properties , the two-stage combustion rate that is the ratio of the total amount of air supplied into the furnace is controlled, and the unburned content in the coal ash A coal combustion apparatus characterized in that the ash is adjusted to obtain coal ash having a desired brain value.
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